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GDP growth in 2026? — 4.6 to 5.0

KXGDPYEAR-26-B4.8 · Economics · 2026-04-20
2%
Agent
2%
Market Price
+0.5%
Edge
78%
Confidence
Volume: 18,816
Spread: 1.6c
Days to resolution: 314
Markets in event: 14
Final Rationale
US real GDP growth landing in the narrow 4.6-5.0% window is historically rare (only ~2-3 occurrences in 40 years, typically post-recession rebounds), and 2026 consensus forecasts cluster around 1.5-2.5% with no recession to rebound from. I partially accept the critique that my 20% nominal-GDP hedge was overweighted — the market's sharp repricing to 2% likely confirms the real-GDP interpretation, and I also accept that Q1 2026 data I cannot access is driving informed trading downward. I move from 3.3% toward 2.5%, closing most of the gap with the market since the medium-reliability market price incorporates information (Q1 data) that my independent forecast lacked.
Price vs. prediction
How the market moved after the agent's call. Solid blue line is the actual market price; dashed line is the agent's static forecast at $t{=}0$.
$n = 58$ follow-ups
1. Planner Opus · Fermi decomposition + tool plan
Tools chosen: article_search kalshi_data
Sub-questions (Fermi decomposition)
  1. GDP growth in 2026? — 4.6 to 5.0 (w=1.00)
Planner reasoning
Fallback: general forecasting approach
2. Research Parallel tool calls · legacy v2
ToolStatusTimeItemsSummary
article_search OK 0.0s -
kalshi_data OK 0.2s -
3. Evidence Synthesis Sonnet · 3 items · legacy v2
#StrengthCredibilityDirectionSourceClaimPriced In
1 STRONG 72 ↓ DOWN kalshi_data The Kalshi prediction market currently prices GDP growth of 4.6–5.0% in 2026 at only 2%, down sharply from 22% at some prior point, with a 30-day decline of 20 percentage points. Yes
2 STRONG 70 ↓ DOWN kalshi_data The 7-day price change is -1% and the 30-day price change is -20%, indicating a strong and sustained shift in market consensus away from this GDP range. Yes
3 WEAK 20 NEUTRAL article_search No articles were found providing macroeconomic forecasts or GDP data for 2026, leaving a significant evidence gap from traditional news/analyst sources. No
Information Gaps
  • No GDP forecast data from official sources (IMF, World Bank, CBO, Fed) for 2026 annual growth
  • No consensus economist survey data (e.g., Bloomberg, Reuters polls) on 2026 GDP growth expectations
  • No quarterly GDP actuals or advance estimates for 2026 to anchor annual projections
  • No context on what event or data shift caused the sharp 30-day drop in market probability (from ~22% to 2%)
  • No information on which country's GDP this refers to — assumed US but not confirmed in the question description
  • No data on trade policy, fiscal stimulus, or monetary policy changes that could affect 2026 GDP
Key Uncertainties
  • The country/region for this GDP question is not explicitly stated — different countries have very different baseline growth rates
  • If this is US GDP, annual real growth of 4.6–5.0% would be historically exceptional and far above consensus estimates
  • If this is a nominal or emerging market GDP measure, the range becomes more plausible but still uncertain
  • What drove the massive 30-day price decline in the market — new macro data, policy changes, or model resets
  • Potential tail risks (recession, geopolitical shock, tariff escalation) that could push growth far below this range
  • Whether the question resolves on real or nominal GDP, and which data source/vintage is used for resolution
Market Context
Price: 0.02 · 7d: -0.01 · 30d: -0.20
Volume: MODERATE — ~993 contracts/day average · Depth: UNKNOWN — not provided in data
Reliability: MEDIUM — moderate volume and 18 data points, but the extreme price drop and low current price suggest potential illiquidity or a structural repricing event that may not fully reflect informed trading
4. Independent Forecaster Opus · No market price · legacy v2 Did NOT see market price
Independent estimate: 3% (72% confidence)
base rate
4%
70% conf
evidence driven
3%
75% conf
contrarian
3%
70% conf
Spread
1pp
Low disagreement
sq1: GDP growth in 2026? — 4.6 to 5.0
4%
Assuming this refers to US real GDP growth (most common default for unspecified GDP questions on prediction markets). Base rate: US annual real GDP growth has been in the 4.6-5.0% range only a handful of times in the past 40 years — notably 1984 (7.2%), 1999 (4.8%), 2021 (5.8% post-COVID rebound). Excluding post-recession rebounds, hitting 4.6-5.0% is extremely rare, roughly 1-2 times in 40 years, giving a base rate of ~3-5%. Consensus forecasts for 2026 US GDP growth from IMF, Fed, CBO, and private economists have been in the 1.5-2.5% range. The range 4.6-5.0 is also a narrow 0.4 percentage point window, which further reduces probability. No recession rebound conditions apparent — 2025 was not a recession year. Evidence gap noted but no indication of extraordinary conditions. If this is nominal GDP, 4.6-5.0% is more plausible (base rate ~15-20%) as nominal growth = real + inflation, and ~2% real + ~2.5% inflation gets near this range. Weighting 80% real / 20% nominal interpretation: 0.8 * 0.03 + 0.2 * 0.15 = 0.054. Adjusting slightly down for narrow window: 4%.
Show full reasoning trace
base rate: US real GDP growth hitting a narrow 0.4pp window of 4.6-5.0% is historically rare — occurring maybe 2-3 times in the past 40 years, typically in post-recession rebound years. Base rate ~3-5%.
evidence updates: No specific evidence found. Consensus 2026 US GDP forecasts cluster around 1.5-2.5%, well below this range. No recession in 2025 to set up a rebound. Narrow band further reduces probability.
combination method: Single sub-question, direct pass-through.
final: Probability of US 2026 real GDP growth landing in 4.6-5.0% range is very low, ~4%. Slight upward adjustment from pure base rate only if nominal GDP interpretation is used.
ensemble: {'ensemble_count': 3, 'perspectives': {'base_rate': {'p_yes': 0.04, 'confidence': 0.7}, 'evidence_driven': {'p_yes': 0.03, 'confidence': 0.75}, 'contrarian': {'p_yes': 0.03, 'confidence': 0.7}}, 'spread': 0.01, 'individual_p_yes': {'base_rate': 0.04, 'evidence_driven': 0.03, 'contrarian': 0.03}}
5. Devil's Advocate Sonnet · legacy v2 Market price revealed
Missing Info Time Awareness Issue
Challenges
  1. The forecaster assumes US GDP without confirmation. Many Kalshi-style 'GDP growth' bucket questions refer to US real GDP, but the 4.6-5.0 bucket existing as a tradeable outcome suggests the market maker considered it plausible enough to list — which is weak evidence but worth noting.
  2. The 20% weight on 'nominal GDP' interpretation may be too high. If the question were nominal, the bucket 4.6-5.0 would actually be quite likely (near consensus nominal growth), and the market would not be pricing it at 2%. The market's low price is itself evidence that this is the real GDP interpretation, suggesting the blended estimate should lean closer to the 3-4% real-only base rate.
  3. Time awareness: we are already in April 2026. Q1 2026 GDP data should be available or nearly so. The forecaster does not incorporate any actual 2026 data, which is a significant gap given 314 days to resolution but ~25% of the year already elapsed.
  4. The 30-day market drop of -20% (from ~22% to 2%) likely reflects incoming Q1 data or updated forecasts. The forecaster flags this information gap but doesn't widen uncertainty to account for it — instead maintaining 0.717 confidence.
Suggested adjustment: -0pp
Minor downward adjustment warranted because (1) the nominal-GDP interpretation weight of 20% is likely too high given the market's low pricing implicitly confirms the real-GDP interpretation, and (2) we're 4 months into 2026 with presumably weak Q1 data driving the market repricing. The forecaster's 3.3% is already close to the market's 2%, so only a small adjustment is needed — not because of market conformity but because the nominal-interpretation hedge appears overweighted.
Market comparison: Forecaster: 3.3%, Market: 2.0%. Divergence is small (+1.3pp) and largely explained by the forecaster's 20% weight on a nominal-GDP interpretation. The market's sharp 30-day drop suggests incoming 2026 data has updated expectations downward, which the forecaster could not access. Divergence is reasonable but slightly favors the market.
6. Aggregator Opus · final calibrated forecast
2% (78% confidence)
US real GDP growth landing in the narrow 4.6-5.0% window is historically rare (only ~2-3 occurrences in 40 years, typically post-recession rebounds), and 2026 consensus forecasts cluster around 1.5-2.5% with no recession to rebound from. I partially accept the critique that my 20% nominal-GDP hedge was overweighted — the market's sharp repricing to 2% likely confirms the real-GDP interpretation, and I also accept that Q1 2026 data I cannot access is driving informed trading downward. I move from 3.3% toward 2.5%, closing most of the gap with the market since the medium-reliability market price incorporates information (Q1 data) that my independent forecast lacked.